When Hurricane Floyd ripped through North Carolina in 1999, more than 4,000 destroyed homes were uninsured or underinsured. Much of the blame lay with maps produced by the federal government to show which properties stood in areas at high risk for flooding.
Those maps, state officials said, were badly outdated, so thousands of property owners who should have bought flood insurance hadn't.
"About 80 percent of all the homes either damaged or destroyed were not shown in the special flood hazard areas," said John Dorman, program director at the North Carolina Floodplain Mapping Program.
Development, road construction and natural forces continually reshape a waterway's floodplain. But the printed maps of high-risk areas, which dictate which property owners must carry flood insurance, were about 13 years old when Floyd hit, Dorman said.
Nor did those maps precisely represent the height of the land. In some places, Dorman said, the elevation was off by 10 feet. In the eastern part of the state, a mere two feet could mean the difference between dry land and an entire county underwater.
One year after Floyd, North Carolina launched a major effort to build accurate digital maps of state flood hazard areas. The state became a cooperating technical partner (CTP) within the Flood Hazard Mapping Modernization Program at the Federal Emergency Management Agency. FEMA made North Carolina responsible for the flood insurance rate maps (FIRMs) covering the state's watersheds. The state started developing digital FIRMs (DFIRMs), which it can update as conditions change.
So far, North Carolina has created preliminary versions of DFIRMs for 29 counties, and offers the data on the Web for free. Officials hope to complete DFIRMs for all North Carolina counties by 2007, Dorman said, and also plan to update definitive floodplain maps every 18 to 24 months.
The main purpose of a FIRM is to help mortgage lenders determine which properties fall into Special Flood Hazard Areas. To get a federally backed mortgage on a property in one of those areas, the purchaser must buy flood insurance. Communities that participate in FEMA's National Flood Insurance Program (NFIP) develop floodplain management plans, with ordinances to regulate development in flood-prone areas. The NFIP helps property owners and renters in participating communities buy flood insurance at moderate rates.
When rising waters ravage uninsured properties, owners often lack money to rebuild.
"It puts the onus back on the community, or the state or federal government, to support those people," Dorman said.
State and local governments are joining the Flood Hazard Mapping Program so after a flood, owners can rely on insurance settlements rather than government aid. That could save North Carolina taxpayers a lot of money, Dorman said, citing a study by the U.S. Geological Survey that determined if the maps were updated and kept current on a statewide basis, a cost avoidance of $56 million per year from flood damage would result.
To get its program going, North Carolina signed a CTP agreement with FEMA. The state Legislature created the Floodplain Mapping Program, and the new program created a Cooperating State Technical Committee. This group of about 50 represents federal, state, county, municipal and private-sector organizations was designed to bring all stakeholders to the table.
North Carolina is developing DFIRMs in three phases. Phase one covers the six river basins in the eastern part of the state. Phase two will focus on another six basins in the Piedmont region, and Phase three will cover the western part of the state.
The Legislature initially funded the program with $23 million, later adding another $9 million to move it into Phase two, Dorman said. FEMA has contributed about $18 million.
The program contracted with two firms -- Watershed Concepts and Greenhorne & O'Mara -- to collect the necessary